In the prior art relating to the construction of buildings, vehicles, and other types of enclosures where control of heat flow and sound transmission is important, various structural arrangements have been proposed for dealing with these factors. Laminated panels with spaced parallel portions for forming dead air spaces have been employed. Also, interlocking modules with hollow sections have been proposed. Hollow glass building blocks have been widely employed in wall structures. Vacuum cells or building blocks have been likewise proposed for constructing an insulating wall.
In general, the previously proposed structures have been relatively expensive, excessively heavy, difficult to install, inefficient in insulating properties, and relatively weak in strength, so that there is a definite need for an improved construction for accomplising the required purposes, mainly with respect to providing satisfactory heat and sound insulation at low cost.
There is also a need for energy conservation in general, and important programs are under way to develop fuel-conserving walls, ceilings and floors for new buildings as well as for the modification of existing buildings to reduce their fuel requirements under cold weather conditions and to facilitate and reduce the energy costs for cooling the buildings by air conditioning equipment under hot weather conditions. Along with this need are requirements for reduction of fire hazards, restraint against the entry of or penetration by moisture, and protection against the infiltration of vermin and rodents.
A preliminary search of the prior art discloses the following prior U.S. patents, which appear to represent the present state of the art: Walzel, U.S. Pat. No. 896,780 Palmer, U.S. Pat. No. 2,049,863 Keaney, U.S. Pat. No. 2,086,185 Snipischki, U.S. Pat. No. 2,211,177 Weber, U.S. Pat. No. 3,341,395 Weiss, U.S. Pat. No. 3,798,861